How bicycle gears work. Photo: A gear is a pair of wheels with teeth that interlock to increase power or speed. In a bicycle, the pair of gears is not driven directly but linked by a chain. At one end, the chain is permanently looped around the main gear wheel (between the pedals).
Accordingly, what keeps you upright on a bike?
The trail keeps the bike upright for the same reason the gyroscopic effect does. If the bike tips to the left, the trail will force the bike to steer to the left. It will steer into the fall, get its wheels back under it, and stay upright. By all rights, this bike should topple over in a second.
Why does a bike balance?
Scientists believe that it's the forward spinning motion of the wheels that helps to keep the bike balanced. On the other hand, it has also been shown that the gyroscopic effect of a bicycle's wheel is all but cancelled out by the weight of the rider's body as well as the force pushing down on the front handlebars.
What is a gyroscopic effect?
The gyro effect, where it becomes difficult to change a spinning object's axis of rotation, is a fascinating thing. But it's taken me a long time to find an intuitive explanation for how it works. Everyone explains it in terms of addition of angular momentum vectors, such as on Wikipedia.